Light Refraction: What is Light Refraction? – Education and Transformation

THE light refraction it is a phenomenon that occurs when light undergoes a change from the propagation medium, from the incidence medium to the refraction medium.

This is where the propagation speed variation takes place.

Light is a waveform that manifests itself at a certain speed and this speed will depend on the medium where it is advertisement.

The speed of light in air is different from light in water so that when passing from one medium to another, for example, a glass with water, refraction or deflection of the light beam occurs.

Here, the speed of light and the wavelength are reduced, but the frequency, which is the constant of proportionality, will not change.

This is why we put an object in a glass of water. We have the illusion that the object is broken.

See too:

• Magnetic Force
• Kinetic energy

Incidence

In refraction, there is a change in the speed of light propagation through a deviation from the original direction, the light suffers an angular deviation from the normal line, goes from a transparent medium to a transparent medium different.

If the incidence of light from the normal medium, which presents the angle of incidence equal to zero, the light will not be deflected, its refracted angle will be null.

But when the incidence of light causes an oblique deviation, the luminous ray will get closer to the normal line, leading to a deviation in the luminous trajectory, which is the phenomenon of refraction.

dioptro

Diopter is the interface between two homogeneous and transparent media and according to their surface, diopters are classified into plane, spherical, cylindrical and others.

Laws of refraction

The phenomenon of light refraction has two laws:

• 1st law of light refraction: the incident, refracted and normal ray at the point of incidence are contained in the same plane, they are coplanar. The plane of refracted light and the plane of incidence coincide.
• 2nd law of light refraction: here the value of the deviation suffered by the light refraction. The sines of the angles of incidence and refraction of light are proportional to the velocities.

Index

the index of light refraction determines the relationship between the speed of light in a vacuum and the speed of the medium. The higher the frequency of light, the higher the index of refraction.

Absolute refractive index

The absolute refractive index is represented by n and corresponds to the ratio between the speed of light in a vacuum (c) and the speed of light in the considered medium (v).

This is because the higher the refractive index, the slower the speed of light propagation in that medium. The absolute refractive index always has a value greater than or equal to 1:

n = c/v

n = index of refraction (dimensionless as there is no unit of measure

c = speed of light in vacuum (c = 3.10(8) m/s)

v = speed of light in the middle (m/s)

Relative refractive index

The relative refractive index calculates the index from one medium to the other:

Na, b = na/nb = vb/va

n = refractive index

v = speed of light in the middle (m/s)

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Class Video – Light Refraction